{"product_id":"powerhead-gasket-set-for-johnson-evinrude-omc-brp-outboards-replaces-oem-391300-389556-439085-sierra-18-4303-1","title":"Sierra Powerhead Gasket Set 18-4303-1, Replaces 389556 391300 439085, Johnson\/Evinrude Outboard","description":"\u003cp\u003eThe Sierra Powerhead Gasket Set, part number 18-4303-1, is a complete gasket kit for Johnson\/Evinrude (OMC\/BRP) outboard powerheads. It is designed to restore proper sealing across the powerhead during a rebuild or gasket replacement, helping prevent oil, fuel, and coolant leaks at the mating surfaces it covers. The set includes multiple individually numbered gaskets packaged together as a single kit, including a fuel pump mounting gasket (Sierra 18-0850, equivalent to OEM 303615) and a by-pass cover gasket (Sierra 18-2876), along with the other gaskets needed for the application.\u003c\/p\u003e\u003cp\u003eThis set replaces OEM numbers 389556, 391300, and 439085, so it can be ordered using any of those original part numbers as a reference. It ships as one complete set with a package quantity of 1, making it a straightforward one-part solution for a powerhead gasket job rather than sourcing individual gaskets separately. The set is intended for Johnson\/Evinrude (OMC\/BRP) outboard engines.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-4303-1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Powerhead Gasket Set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Outboard - Johnson\/Evinrude (OMC\/BRP)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.91 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282259167\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContents:\u003c\/strong\u003e Fuel Pump Mounting Gasket (18-0850, O.E. 303615, Qty 1), By-Pass Cover Gasket (18-2876), plus additional powerhead gaskets included in the set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 389556, 391300, 439085\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eJohnson\/Evinrude (OMC\/BRP) outboard engines\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e389556\u003c\/li\u003e\n\u003cli\u003e391300\u003c\/li\u003e\n\u003cli\u003e439085\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is included in the Sierra 18-4303-1 Powerhead Gasket Set?\u003c\/strong\u003e The set includes a fuel pump mounting gasket (Sierra 18-0850, equivalent to OEM 303615) and a by-pass cover gasket (Sierra 18-2876), along with the other gaskets needed for a Johnson\/Evinrude outboard powerhead job, all packaged together as one kit with a package quantity of 1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich OEM part numbers does 18-4303-1 replace?\u003c\/strong\u003e Sierra 18-4303-1 replaces OEM numbers 389556, 391300, and 439085, so any of those numbers can be used to confirm this is the correct set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engines is the 18-4303-1 Powerhead Gasket Set designed for?\u003c\/strong\u003e This gasket set is designed for Johnson\/Evinrude (OMC\/BRP) outboard engines that use the powerhead gaskets covered under Sierra part number 18-4303-1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-4303-1 gasket set weigh?\u003c\/strong\u003e The complete set weighs 0.91 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a complete powerhead gasket kit or a single gasket?\u003c\/strong\u003e It is a complete set containing multiple gaskets, including the fuel pump mounting gasket and by-pass cover gasket, rather than a single individual gasket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I order this set using OEM number 391300 or 389556 instead of the Sierra number?\u003c\/strong\u003e Yes, part number 18-4303-1 is the direct equivalent to OEM numbers 391300, 389556, and 439085, so ordering by any of those numbers will get you this same set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-4303-1 gasket set genuine Sierra manufacturing or a generic aftermarket copy?\u003c\/strong\u003e It is manufactured by Sierra under part number 18-4303-1 as a direct-fit aftermarket replacement for the listed OEM numbers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the package quantity for this gasket set?\u003c\/strong\u003e The Sierra 18-4303-1 Powerhead Gasket Set ships with a package quantity of 1 complete set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-4303-1 set include the by-pass cover gasket?\u003c\/strong\u003e Yes, the by-pass cover gasket, Sierra part 18-2876, is included as part of the 18-4303-1 Powerhead Gasket Set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the fuel pump mounting gasket's OEM equivalent in this set?\u003c\/strong\u003e The fuel pump mounting gasket included in this set is Sierra 18-0850, which corresponds to OEM number 303615.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988193587419,"sku":"SIE-18-4303-1","price":129.71,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-4303-1_lg__25798.1722382921.500.750.jpg?v=1785187996","url":"https:\/\/www.goodvibesmarina.com\/products\/powerhead-gasket-set-for-johnson-evinrude-omc-brp-outboards-replaces-oem-391300-389556-439085-sierra-18-4303-1","provider":"Good Vibes Marina","version":"1.0","type":"link"}